Radiation metabolomics. 2. Dose- and time-dependent urinary excretion of deaminated purines and pyrimidines after sublethal gamma-radiation exposure in mice

Gamma-radiation exposure of humans is a major public health concern as the threat of terrorism and potential hostile use of radiological devices increases worldwide. We report here the effects of sublethal gamma-radiation exposure on the mouse urinary metabolome determined using ultra-performance liquid chromatography-coupled time-of-flight mass spectrometry-based metabolomics. Five urinary biomarkers of sublethal radiation exposure that were statistically significantly elevated during the first 24 h after exposure to doses ranging from 1 to 3 Gy were unequivocally identified by tandem mass spectrometry. These are deaminated purine and pyrimidine derivatives, namely, thymidine, 2'-deoxyuridine, 2'-deoxyxanthosine, xanthine and xanthosine. Furthermore, the aminopyrimidine 2'-deoxycytidine appeared to display reduced urinary excretion at 2 and 3 Gy. The elevated biomarkers displayed a time-dependent excretion, peaking in urine at 8-12 h but returning to baseline by 36 h after exposure. It is proposed that 2'-deoxyuridine and 2'-deoxyxanthosine arise as a result of gamma irradiation by nitrosative deamination of 2'-deoxycytidine and 2'-deoxyguanosine, respectively, and that this further leads to increased synthesis of thymidine, xanthine and xanthosine. The urinary excretion of deaminated purines and pyrimidines, at the expense of aminopurines and aminopyrimidines, appears to form the core of the urinary radiation metabolomic signature of mice exposed to sublethal doses of ionizing radiation.

High expression of gastrin-releasing peptide receptors in the vascular bed of urinary tract cancers: promising candidates for vascular targeting applications

Tumoral gastrin-releasing peptide (GRP) receptors are potential targets for diagnosis and therapy using radiolabeled or cytotoxic GRP analogs. GRP-receptor overexpression has been detected in endocrine-related cancer cells and, more recently, also in the vascular bed of selected tumors. More information on vascular GRP-receptors in cancer is required to asses their potential for vascular targeting applications. Therefore, frequent human cancers (n = 368) were analyzed using in vitro GRP-receptor autoradiography on tissue sections with the (125)I-[Tyr(4)]-bombesin radioligand and/or the universal radioligand (125)I-[d-Tyr(6), beta-Ala(11), Phe(13), Nle(14)]-bombesin(6-14). GRP-receptor expressing vessels were evaluated in each tumor group for prevalence, quantity (vascular score), and GRP-receptor density. Prevalence of vascular GRP-receptors was variable, ranging from 12% (prostate cancer) to 92% (urinary tract cancer). Different tumor types within a given site had divergent prevalence of vascular GRP-receptors (e.g. lung: small cell cancer: 0%; adenocarcinoma: 59%; squamous carcinoma: 83%). Also the vascular score varied widely, with the highest score in urinary tract cancer (1.69), moderate scores in lung (0.91), colon (0.88), kidney (0.84), and biliary tract (0.69) cancers and low scores in breast (0.39) and prostate (0.14) cancers. Vascular GRP-receptors were expressed in the muscular vessel wall in moderate to high densities. Normal non-neoplastic control tissues from these organs lacked vascular GRP-receptors. In conclusion, tumoral vessels in all evaluated sites express GRP-receptors, suggesting a major biological function of GRP-receptors in neovasculature. Vascular GRP-receptor expression varies between the tumor types indicating tumor-specific mechanisms in their regulation. Urinary tract cancers express vascular GRP-receptors so abundantly, that they are promising candidates for vascular targeting applications.

Combined ultrasmall superparamagnetic particles of iron oxide-enhanced and diffusion-weighted magnetic resonance imaging reliably detect pelvic lymph node metastases in normal-sized nodes of bladder and prostate cancer patients

BACKGROUND: Lymph node staging of bladder or prostate cancer using conventional imaging is limited. Newer approaches such as ultrasmall superparamagnetic particles of iron oxide (USPIO) and diffusion-weighted magnetic resonance imaging (DW-MRI) have inconsistent diagnostic accuracy and are difficult to interpret. OBJECTIVE: To assess whether combined USPIO and DW-MRI (USPIO-DW-MRI) improves staging of normal-sized lymph nodes in bladder and/or prostate cancer patients. DESIGN, SETTING, AND PARTICIPANTS: Twenty-one consecutive patients with bladder and/or prostate cancer were enrolled between May and October 2008. One patient was excluded secondary to bone metastases detected on DW-MRI with subsequent abstention from surgery. INTERVENTION: Patients preoperatively underwent 3-T MRI before and after administration of lymphotropic USPIO using conventional MRI sequences combined with DW-MRI. Surgery consisted of extended pelvic lymphadenectomy and resection of primary tumors. MEASUREMENTS: Diagnostic accuracies of the new combined USPIO-DW-MRI approach compared with the "classic" reading method evaluating USPIO images without and with DW-MRI versus histopathology were evaluated. Duration of the two reading methods was noted for each patient. RESULTS AND LIMITATIONS: Diagnostic accuracy (90% per patient or per pelvic side) was comparable for the classic and the USPIO-DW-MRI reading method, while time of analysis with 80 min (range 45-180 min) for the classic and 13 min (range 5-90 min) for the USPIO-DW-MRI method was significantly shorter (p<0.0001). Interobserver agreement (three blinded readers) was high with a kappa value of 0.75 and 0.84, respectively. Histopathological analysis showed metastases in 26 of 802 analyzed lymph nodes (3.2%). Of these, 24 nodes (92%) were correctly diagnosed as positive on USPIO-DW-MRI. In two patients, one micrometastasis each (1.0x0.2 mm; 0.7x0.4 mm) was missed in all imaging studies. CONCLUSIONS: USPIO-DW-MRI is a fast and accurate method for detecting pelvic lymph node metastases, even in normal-sized nodes of bladder or prostate cancer patients.

Human urinary metabolomic profile of PPARalpha induced fatty acid beta-oxidation

Activation of the peroxisome proliferator-activated receptor alpha (PPARalpha) is associated with increased fatty acid catabolism and is commonly targeted for the treatment of hyperlipidemia. To identify latent, endogenous biomarkers of PPARalpha activation and hence increased fatty acid beta-oxidation, healthy human volunteers were given fenofibrate orally for 2 weeks and their urine was profiled by UPLC-QTOFMS. Biomarkers identified by the machine learning algorithm random forests included significant depletion by day 14 of both pantothenic acid (>5-fold) and acetylcarnitine (>20-fold), observations that are consistent with known targets of PPARalpha including pantothenate kinase and genes encoding proteins involved in the transport and synthesis of acylcarnitines. It was also concluded that serum cholesterol (-12.7%), triglycerides (-25.6%), uric acid (-34.7%), together with urinary propylcarnitine (>10-fold), isobutyrylcarnitine (>2.5-fold), (S)-(+)-2-methylbutyrylcarnitine (5-fold), and isovalerylcarnitine (>5-fold) were all reduced by day 14. Specificity of these biomarkers as indicators of PPARalpha activation was demonstrated using the Ppara-null mouse. Urinary pantothenic acid and acylcarnitines may prove useful indicators of PPARalpha-induced fatty acid beta-oxidation in humans. This study illustrates the utility of a pharmacometabolomic approach to understand drug effects on lipid metabolism in both human populations and in inbred mouse models.

Detection of urinary stones at reduced radiation exposure: a phantom study comparing computed radiography and a low-dose digital radiography linear slit scanning system

OBJECTIVE: In this experimental study we assessed the diagnostic performance of digital linear slit scanning radiography compared with computed radiography (CR) for the detection of urinary calculi in an anthropomorphic phantom imitating patients weighing approximately 58-88 kg. CONCLUSION: Compared with CR, linear slit scanning radiography is superior for the detection of urinary stones and may be used for pretreatment localization and follow-up at a lower patient exposure.

Vaginal voiding: a common cause of daytime urinary leakage in girls

STUDY OBJECTIVE: To estimate the frequency of vaginal voiding as the cause of daytime urinary leakage in girls, and to study the effect of instructions intended to alleviate the problem. SETTING: Girls with vaginal voiding were identified in a group of girls referred because of daytime urinary leakage. They were evaluated by a noninvasive screening protocol. Girls with vaginal voiding were instructed on how to achieve better toilet habits. PARTICIPANTS: Twelve girls with vaginal voiding. RESULTS: Vaginal voiding was found in 12 of 39 girls with daytime urinary leakage. Their age ranged between 8.5 and 13.9 years. They all had history of small leakage immediately after voiding. A body mass index greater than the corresponding 85th percentile was noted in 5 girls, and labial fusion was noted in 2 girls. The complaint disappeared in 10 girls and improved in the remaining 2 girls after instructions on how to achieve better toilet habits. CONCLUSIONS: Vaginal voiding is common in girls. It occurs in girls at risk of overweight, in girls with labial fusion, and in girls adopting a hairpin posture while sitting on the toilet. The diagnosis is obtained by an adequate history. Proper voiding instructions resolve the problem.

The prognostic value of cytology and fluorescence in situ hybridization in the follow-up of nonmuscle-invasive bladder cancer after intravesical Bacillus Calmette-Guérin therapy

Molecular markers reliably predicting failure or success of Bacillus Calmette-Guérin (BCG) in the treatment of nonmuscle-invasive urothelial bladder cancer (NMIBC) are lacking. The aim of our study was to evaluate the value of cytology and chromosomal aberrations detected by fluorescence in situ hybridization (FISH) in predicting failure to BCG therapy. Sixty-eight patients with NMIBC were prospectively recruited. Bladder washings collected before and after BCG instillation were analyzed by conventional cytology and by multitarget FISH assay (UroVysion, Abbott/Vysis, Des Plaines, IL) for aberrations of chromosomes 3, 7, 17 and 9p21. Persistent and recurrent bladder cancers were defined as positive events during follow-up. Twenty-six of 68 (38%) NMIBC failed to BCG. Both positive post-BCG cytology and positive post-BCG FISH were significantly associated with failure of BCG (hazard ratio (HR)= 5.1 and HR= 5.6, respectively; p < 0.001 each) when compared to those with negative results. In the subgroup of nondefinitive cytology (all except those with unequivocally positive cytology), FISH was superior to cytology as a marker of relapse (HR= 6.2 and 1.4, respectively). Cytology and FISH in post-BCG bladder washings are highly interrelated and a positive result predicts failure to BCG therapy in patients with NMIBC equally well. FISH is most useful in the diagnostically less certain cytology categories but does not provide additional information in clearly malignant cytology.

Benign prostatic obstruction and parkinson's disease--should transurethral resection of the prostate be avoided?

PURPOSE: According to the literature transurethral resection of the prostate in patients with Parkinson's disease has an increased risk of postoperative urinary incontinence. However, this conclusion might have been reached because some patients with multiple system atrophy incorrectly diagnosed as Parkinson's disease were included in these reports. Therefore, we investigated the outcome of transurethral prostate resection in patients with a secure neurological diagnosis of Parkinson's disease. MATERIALS AND METHODS: A total of 23 patients with Parkinson's disease who underwent transurethral prostate resection for benign prostatic obstruction were evaluated retrospectively. Subsequent neurological developments in patients were followed, ensuring that those with multiple system atrophy had not been included in analysis. RESULTS: At transurethral prostate resection median patient age was 73 years, median duration of Parkinson's disease before the resection was 3 years, and median Hoehn and Yahr scale was 2. Of the 14 patients with a preoperative indwelling urinary catheter transurethral prostate resection restored voiding in 9 (64%) and only 5 (36%) required catheterization postoperatively. Of the 10 patients with preoperative urge urinary incontinence, continence was restored in 5 and improved in 3 following transurethral prostate resection. There were no cases of de novo urinary incontinence after transurethral prostate resection. At a median postoperative followup of 3 years transurethral prostate resection was successful in 16 of the 23 patients (70%). CONCLUSIONS: Transurethral prostate resection for benign prostatic obstruction in patients with Parkinson's disease may be successful in up to 70% and the risk of de novo urinary incontinence seems minimal. Thus, Parkinson's disease should no longer be considered a contraindication for transurethral prostate resection provided that preoperative investigations including urodynamic assessment indicate prostatic bladder outlet obstruction.

Suburothelial myofibroblasts in the human overactive bladder and the effect of botulinum neurotoxin type A treatment

BACKGROUND: An increasing body of evidence suggests a possible role of suburothelial myofibroblasts (MFs) in bladder mechanosensation and in the pathophysiology of detrusor overactivity (DO). OBJECTIVE: To determine whether markers of MFs, including gap junction protein connexin43 (Cx43) and c-kit have altered immunohistochemical expression in the suburothelium of patients with neurogenic DO (NDO) or idiopathic DO (IDO) and whether this is affected by successful treatment of DO with botulinum neurotoxin type A (BoNTA). DESIGN, SETTING, AND PARTICIPANTS: Patients with NDO (n=10) or IDO (n=11) were treated in a single-centre, open-label study of intradetrusor BoNTA injections. Control tissue was obtained from 10 patients undergoing pelvic-floor repair procedures who had no overactive bladder (OAB) symptoms. This study is registered with ClinicalTrials.gov, number NCT00662064. INTERVENTIONS: Bladder biopsies performed with flexible cystoscopes were obtained from control subjects and from NDO and IDO patients before BoNTA treatment and at 4 wk and 16 wk after treatment. They were studied with quantitative immunofluorescence using antibodies to connexin 43 (Cx43), vimentin, and c-kit. MEASUREMENTS: Differences in Cx43, vimentin, and c-kit immunoreactivity between control subjects and NDO or IDO patients (primary outcomes). Changes in NDO or IDO, Cx43 immunoreactivity, and c-kit immunoreactivity after BoNTA treatment (secondary outcomes). RESULTS AND LIMITATIONS: Cx43 immunoreactivity was increased in both IDO and NDO patients compared to controls, but remained unchanged after BoNTA treatment. C-kit immunoreactivity was similar in NDO/IDO patients and controls and remained unchanged after BoNTA treatment. CONCLUSIONS: Increased gap junction formation in the suburothelium has been demonstrated in biopsies from humans with DO. It is hypothesised that this change could have a significant role in the pathogenesis of the detrusor abnormality. Successful treatment of NDO or IDO does not appear to be associated with changes in the expression of Cx43 or c-kit on suburothelial MFs.

Pre- and postnatal therapy of lower urinary tract obstruction - an experience of 18 years

With prenatal detection of hydronephrosis and technological advances in surgical equipment, the management of lower urinary tract obstruction has evolved to include prenatal surgical intervention. Surgical intervention, was based upon the rationale that restoring amniotic fluid to normal levels by shunting fetal urine from the obstructed urinary system to the amniotic space would prevent lung hypoplasia and, thus, improve neonatal survival. Inaddition, relief of the obstruction would also reduce back pressure and reduce injury to the developing nephron, thus improving long-term renal function postnatally. However, this remains investigational, and the vast majority of affected infants are treated soon after birth. We have experience since 1991 with prenatal treatment of megacystis. In 23 cases of 50 detected megacystis with oligohydramnion in male and without other abnormalities a prenatal intervention by bladderpunction and in 12 cases additional vesicoamniotic shunt placement was performed. The prognosis of megacystis with oligohydramnion is stated with a survival rate of 10-30%. In our group 54% (13 children) survived. Also we want present 56 cases of urethral valves with a postnatal transurethral intervention. With a follow up time from 8.6 (3 to 15) years we attend 34 children (60%) with normal renal function, 21% (12) with mild or moderate renal insufficiency and there was a kidney transplantation in 6 cases necessary. With our multidisciplinary presentation we want to discuss the indication, interdisciplinary aspects,risks and the follow up of pre- and postnatal intervention in such cases.

The impact of lymphadenectomy and lymph node metastasis on the outcomes of radical cystectomy for bladder cancer

CONTEXT: The presence of lymph node metastases and the extent of lymphadenectomy have both been shown to influence the outcome of patients with muscle-invasive bladder cancer. OBJECTIVE: Current standards for detection of lymph node metastases, lymph-node mapping studies, histopathologic techniques, and risk factors in relation to lymph node involvement are discussed. The impact of lymph node metastases and the extent of lymphadenectomy on the outcome of patients treated with radical cystectomy are analyzed. EVIDENCE ACQUISITION: A systematic literature review of bladder cancer and lymph nodes was performed searching the electronic databases Pubmed/Medline, Cochrane, and Embase. Articles were selected based on title, abstract, study format, and content by a consensus of all participating authors. EVIDENCE SYNTHESIS: Lymph node status is highly consequential in bladder cancer patients because the presence of lymph node metastases is predictive of poor outcome. Knowledge of primary landing sites of lymph node metastases is important for optimum therapeutic management. Accurate pathologic work-ups of resected lymph node tissue are mandatory. Molecular markers could potentially guide therapeutic decisions in the future because they may enable the detection of micrometastatic disease. In current series, radical cystectomy with an extended lymphadenectomy seems to provide a clinically meaningful therapeutic benefit compared with a limited approach. However, the anatomic boundaries of lymph node dissection are still under debate. Therefore, large prospective multicenter trials are needed to validate the influence of extended lymph node dissection on disease-specific survival. CONCLUSIONS: An extended pelvic lymph node dissection (encompassing the external iliac vessels, the obturator fossa, the lateral and medial aspects of the internal iliac vessels, and at least the distal half of the common iliac vessels together with its bifurcation) can be curative in patients with metastasis or micrometastasis to a few nodes. Therefore, the procedure may be offered to all patients undergoing radical cystectomy for invasive bladder cancer.

[Urinary specific gravity--comparative measurements using reagent strips and refractometer in 340 morning urine samples]

The specific gravity of urine (SG) indicates the number and weight of solute particles in urine; its measurement is helpful in interpreting proteinuria detected by dipstick tests and in monitoring adequate hydration in patients with nephrolithiasis. Four methods for measuring SG or osmolality of urine are currently available (depression of the freezing-point, urometry, refractometry, cation exchange on a reagent strip). Using a recently developed reagent strip, we have measured SG in morning urines of 340 non-selected outpatients and compared the results with SG measurements by refractometry of the same urines. In 86.2% of all urines, a good positive correlation between SG measured by reagent strip and refractometry was noted (r = 0.913, p = 0.0001). In 13.8% of the urines, however, the SG measured by reagent strip deviated by more than +/- 5 from the value obtained by refractometry; in 90% of these urines, glucosuria (reagent strip values too low or too high), proteinuria (values too high), or bacteriuria/leukocyturia (values too low or too high) could be found. In alkaline urine (pH > 7.0), SG values obtained by reagent strip have to be corrected by +5.

No evidence of osteopenia 5 to 8 years after ileal orthotopic bladder substitution

The use of bowel segments as bladder substitutes may result in chronic, impaired vitamin D and calcium metabolism, and ultimately in bone demineralization.